Trihalomethane formation during water disinfection in four water supplies in the Somes river basin in Romania

Abstract

Background, aim and scope After the discovery of chloroform in drinking water, an extensive amount of work has been dedicated to the factors influencing the formation of halogenated disinfections by-products (DBPs). The disinfection practice can vary significantly from one country to another. Whereas no disinfectant is added to many water supplies in Switzerland or no disinfectant residual is maintained in the distribution system, high disinfectant doses are applied together with high residual concentrations in the distribution system in other countries such as the USA or some southern European countries and Romania. In the present study, several treatment plants in the Somes river basin in Romania were investigated with regard to chlorine practice and DBP formation (trihalomethanes (THMs)). Laboratory kinetic studies were also performed to investigate whether there is a relationship between raw water dissolved organic matter, residual chlorine, water temperature and THM formation. Materials and methods Drinking water samples were collected from different sampling points in the water treatment plant (WTP) from Gilau and the corresponding distribution system in Cluj-Napoca and also from Beclean, Dej and Jibou WTPs. The water samples were collected once a month from July 2006 to November 2007 and stored in 40-mL vials closed with Teflon lined screw caps. Water samples were preserved at 4°C until analysis after sodium thiosulfate (Na 2 S 2 O 3 ) had been added to quench residual chlorine. All samples were analysed for THMs using headspace GC-ECD between 1 and 7 days after sampling. The sample (10 mL) was filled into 20-mL headspace vials and closed with a Teflon-lined screw cap. Thereafter, the samples were equilibrated in an oven at 60°C for 45 min. The headspace (1 mL) was then injected into the GC (Cyanopropylphenyl Polysiloxane column, 30 m×53 mm, 3μm film thickness, Thermo Finnigan, USA). The MDLs for THMs were determined from the standard deviation of eight standards at 1μg/L. The MDLs for CHCl 3 , CHBrCl 2 , CHBr 2 Cl and CHBr 3 were 0.3, 0.2, 0.3 and 0.6 μg/L, respectively. All kinetic laboratory studies were carried out only with water from the WTP Gilau. The experiments were conducted under two conditions: baseline conditions (pH7, 21°C, 2.5 mg/L Cl 2 ) to gain information about the change of the organic matter in the raw water and seasonally variable conditions

ESTROM 2008 International Conference

“…Zaharie Moldovan (National Institute for Isotopic and Molecular Technology, Cluj-Napoca, Romania) and Dumitru Ristoiu (University Babes-Bolyai, Cluj-Napoca, Romania) reported on the ESTROM projects PHARMSOMES (Moldovan and Alder 2009) and WAQUA (Ristoiu et al 2009), respectively. A topic lecture was presented by Frajo Wirtz (IAWR, International Association of Waterworks in the Rhine catchment area) presenting the "Danube, Meuse and Rhine MEMORANDUM 2008".…”

<b>Development of Actual Dyestuff Wastewater Treatment by Ozone with Carbonaceous Materials Produced from Waste Fiber</b>

“…Recently, trihalomethanes, which have generated serious concerns about the safety of tap water, have been shown to be carcinogenic substances [6,7]. They are formed during the process of chlorine sterilization and disinfection processing by reactions with organic compounds, for example, dyestuff or humic acid in nature [7][8][9].…”

“…They are formed during the process of chlorine sterilization and disinfection processing by reactions with organic compounds, for example, dyestuff or humic acid in nature [7][8][9]. The wastewater in the textile industry contains not only hazardous materials but also a high concentration of dyestuff and nitrogenous substances.…”

Trihalomethane formation potential in treated water supplies in urban metro city

“…Chlorine, which exists as hypochlorous acid and hypochlorite in water, reacts with natural DOM, such as humic and fulvic acids to form THMs (Gallard and von Gunten 2002;Ristoiu et al 2009). In the presence of bromides in source waters, hypobromous acid is formed when chlorine is used as disinfectant (Westerhoff et al 2004).…”

“…Recently, it has been reported that THMs suspect to cause liver and kidney damage, retarded fetus growth, birth defects, and possibly miscarriage (Wright et al 2004;Ristoiu et al 2009). The rapid growth of Delhi, due to the growing influx of population into the urban city from the neighboring states and also from the other parts of the country, has resulted in significant increase in drinking water demand.…”